[Estimate of seroprevalence of HIV infection in Belgium using the back calculation method].

An estimation of HIV seroprevalence in Belgium in June 1990 was made by the "back calculation method". The theoretical calculation of the number of virus carriers gave a range of values from 5,750 to 16,800 carriers. The upper part of this range seems to be more consistent with data from epidemiologic monitoring (range of values from 8,900 to 16,800 carriers). HIV prevalence rate in Belgium in June 1990 would is estimated between 0.9/1000 and 1.7/1000. The detection rate of the infection among HIV positives individuals should be at least 34%.